The present invention relates to a cooling heating device which cools a cool target by heat absorption of a refrigerant in an evaporator of a vapor compression type refrigeration cycle (vapor-compression refrigeration cycle) and which heats a heat target by heat radiation of the refrigerant in a condenser (or condensing heat exchanger or gas cooler or gas cooling heat exchanger).
In general, a freezing device has broadly been used in which a vapor compression type refrigeration cycle is used as a method such as cooling or freezing to cool a cool target. In this type of freezing device, the cool target is cooled by an evaporating function of a refrigerant in an evaporator, and heat generated by condensation of the refrigerant in a condenser is released to atmospheric air or the like.
Moreover, as a method such as heating or hot water supply to heat a heat target, a heat pump device is used in which the vapor compression type refrigeration cycle is used. In this type of heat pump device, the heat target is heated by a heat radiating function in a case where the refrigerant rejects heat to condense in the condenser, and the heat is absorbed from a heat source such as the atmospheric air by evaporation of the refrigerant in the evaporator.
In the above freezing device, during a cooling operation, the heat generated at a time when the refrigerant rejects the heat to condense in the condenser is released to the atmospheric air. Therefore, there has been a problem that energy is not effectively used and that rise of an ambient temperature is incurred.
On the other hand, in the above heat pump device, a heat absorbing function obtained at a time when the refrigerant evaporates in the evaporator during a heat pump operation is not effectively used at all, and the heat is simply pumped up from the atmospheric air.
To solve the problem, a cooling heating device is developed in which the heat rejected (transferred) on a high-pressure side of the refrigeration cycle is effectively used even during the cooling operation, and energy saving is achieved (see, e.g., Japanese Patent Application Laid-Open Nos. 2004-309093 and 2004-340470). In the cooling heating device constituted so that cooling and heating are simultaneously performed using the refrigeration cycle, the cool target is cooled by the evaporating function of the refrigerant in the evaporator of the refrigeration cycle. Moreover, the heat target can be heated by the heat rejected from the refrigerant in the condenser. Therefore, the heat generated on the high-temperature side of the refrigeration cycle in a cooling process, which has heretofore been released into the atmospheric air without being used, can effectively be used, and reduction of consumption of the energy can be expected.
However, the energy consumption can be reduced as described above in a case where the cooling and the heating are simultaneously performed. However, in a case where the cooling operation involving the heat radiation in an outdoor air heat exchanger (an operation in which the only cooling is used) or a heating operation involving the heat absorption in an air heat exchanger (an operation in which the only heating is used) is performed, it cannot be said that the energy is effectively used.
Especially, required cooling and heating loads are not necessarily balanced thermally cyclically, and the respective loads are not necessarily generated at the same time. Therefore, even in the cooling heating device constituted so that the cooling and the heating are simultaneously performed, the cooling operation and the heating operation are not frequently performed at the same time. Therefore, it has actually been difficult to perform an efficient operation.